Aquatic harvester with improved flotation system

ABSTRACT

An improved aquatic harvester is disclosed having an aquatic craft comprising a plurality of pontoons secured below a flat deck member, a pick-up assembly mounted on the forward end of the craft to collect aquatic material both at and below the surface of the water and an above-the-water propulsion and steering system having an air propulsion unit. The improvement resides in the design of the pontoon members from at least one closed, integrally formed buoyant capsule constructed of a plastic material.

United States Patent 1 [111 3,890,771 Kelpin 1*June 24, 1975 [54]AQUATIC HARVESTER WITH IMPROVED 3,467,345 9/1969 Windecker 114/665 F XFLOTATON SYSTEM 3,477,213 11/1969 lust et a1 1.

3,698,163 10/1972 Kelpin 56/9 [76] lnventor: Thomas G. Kelpin, 8877Boyonne Dr., Shreveport, La. 71 108 FOREIGN PATENTS OR APPLICATIONS I 1Notice: The portion of the term of this 450,788 4/1968 Switzerland 56/9patent subsequent to Oct, 17, 1989, h b di l i d Primary ExaminerL0uisG. Mancene Assistant ExaminerJ, N. Eskovitz [2n F'led: 1973 Attorney,Agent, or Firm--Richard L. Schwaab [21] Appl. No.: 325,066

[57] ABSTRACT {52] U.S. Cl. .1 56/9; 114/665 F; 1 15/3 An improvedaquatic harvester is disclosed having an [51] lift. Cl A0111 aquaticcrafi Comprising a plurality of pcntoons [58] Flew of Search 56/8 9; F;cured below a Hat deck member, a pickup assembly 115/5 3 mounted on theforward end of the craft to collect aquatic material both at and belowthe surface of the l56l References Cned water and an above-the-waterpropulsion and steering UNITED STATES PATENTS system having an airpropulsion unit. The improve- 1,842,125 1/1932 Schwarz 115/3 X men!resides in the design of the pontoon members 3,090,339 5/1963 Carr114/665 F from at least one closed, integrally formed buoyant 15,86012/1963 Payne A 4 r 4 F capsule constructed of a plastic materialv3,270,827 9/1966 Mantle v 115/.5 A X 3,304,900 2/1967 Greenwood 114/665F 11 Claims, 16 Drawing Figures PATENTEDJUN24 1975 SHEET 7 FIG. I

FIG.2

PATENTED JUN 2 4 I975 SHEET PATENTED JUN 24 ms i; Q n SHEET i 52 IF|G.l6

1 AQUATIC HARVESTER WITH IMPROVED FLOTATION SYSTEM BACKGROUND OF THEINVENTION The present invention relates to an improved apparatus forharvesting aquatic material, and more especially to an improvement ofthe aquatic harvester disclosed in my U.S. Pat. No. 3,698,163. Theaquatic harvester forming the basis for the foregoing patent representsa revolutionary and highly advantageous design for a device forefficiently cutting and harvesting underwater marine plant life,primarily in inland lakes and waterways and also in coastal waterways.The harvester comprises an aquatic craft comprising a plurality ofpontoons secured longitudinally to the bottom of a flat deck member withthe craft being propelled and steered exclusively by a totallyabove'the-water air propulsion system. As a result of these designfeatures, the harvester is capable of operating and being easilymaneuvered in extremely shallow water while the possibility is minimizedthat the craft may become fouled with excessive weed growth, floatingobjects, or hidden underwater obstacles. At the same time, the harvesteris capable of carrying payloads in excess of ten tons.

In designing the original harvester, a pontoon structure was soughtwhich would produce an extremely light weight pontoon, yet one which wascapable of withstanding the rigors to which the craft was destined to besubjected to as a result of its intended use as well as to providesufficient buoyancy to carry the payloads of harvested material forwhich the craft was designed. The pontoon design employed with the priorharvester comprised a continuous length of spirally wound, corrugatedwall conduit having folded and crimped seams along the spiral lines ofconstruction. Despite the fact that this particular design fulfilled therequirements set forth above, certain disadvantages nonetheless apear inconnection with the use of the harvester fitted with this type ofpontoon. For example, in the event that some hidden obstacle was in factstruck with the harvester sufficiently hard to damage the pontoon, as bycausing a rupture thereof, the loss of the entire buoyant affect of thedamaged pontoon member resulted. While pontoon members of this typecould be compartmentalized, this is both relatively difficult andexpensive to accomplish. In addition, damage to one compartment of sucha compartmentalized pontoon member still requires shutdown of the entireapparatus while the damage is being repaired. It was therefore desiredto design a flotation system for the subject aquatic harvester which,without sacrificing in the lightness of weight or buoyancy capacity ofthe spirally wound conduit, would overcome the aforementioneddisadvantages attendant thereto.

SUMMARY OF THE INVENTION Accordingly it is an object of the presentinvention to provide an aquatic harvester having an improved pontoonflotation system.

Another object of the present invention is to provide an aquaticharvester having a pontoon flotation system which is extremely lightweight and buoyant and at the same time resists adverse affects upon theoperation of the harvester when a portion of the pontoon is damaged.

Yet another object of this invention is to provide an aquatic harvesterhaving a pontoon flotation system which permits easy replacement of eachpontoon or segment of a pontoon in the event of damage thereof, therebyavoiding down-time for the harvester apparatus.

In accomplishing the foregoing objects, there has been providedaccording to the present invention an aqutatic harvester which comprisesan aquatic craft having a plurality of pontoon members securedlongitudinally beneath a deck member, a pick-up assembly mounted on thedeck of the craft for picking up aquatic material both at and below thesurface of the water and an above-the-water propulsion and steeringsystem having an air propulsion unit. Each of the pontoon memberscomprises at least one closed, integrally formed buoyant capsuleconstructed of a thermoplastic or suitable thermosetting syntheticresinous material. Preferably, each pontoon consists of a plurality ofthese thermoplastic synthetic resinous capsules. In one design of suchcapsules, they may consist of an integral molded exterior shellsurrounding an internal cavity, or the internal capacity may bepartially or completely filled with a foamed material such as a foamedsynthetic resinous material, e.g., foamed polystyrene or polyurethane.The exterior shell of the pontoons is preferably a high impact materialsuch as polyethylene.

Other objects, features and advantages of the present invention willbecome apparent from the description hereinbelow when taken inconjunction with the accompanying drawings wherein like referencenumerals are used to indicate like or equivalent parts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, partially cutaway, of an aquatic harvester according to the invention, illustratingin phantom lines the unloading position for the pick-up assembly;

FIG. 2 is a right side view of FIG. 1;

FIG. 3 is a top view of the aquatic craft portion of an aquaticharvester according to this invention;

FIG. 4 is a view taken along the line 4-4 in FIG. 1;

FIG. 5 is a perspective view of two pontoon sections according to thepresent invention;

FIG. 6 is a cross sectional view taken along the line 66 in FIG. 5;

FIG. 7 is a detailed view, partially in section, illustrat ing theactuator means for the pick-up assembly with the unloading position ofthe assembly illustrated in phantom lines;

FIG. 8 is a skeleton view of FIG. 7 illustrating the path of theactuator chain;

FIG. 9 is a detailed view of the truss member securing the pontoonsections to the harvester;

FIG. 10 is a detailed side view of the engine and air propellerassembly;

FIG. 11 is a top view of FIG. 10;

FIG. I2 is a view along the line 12-12 of FIG. 10, illustrating thesteering control assembly;

FIG. 13 is a view along the line l3l3 of FIG. I2;

FIG. 14 is a top view of a chain tightener employed in conjunction withthe steering control assembly;

FIG. 15 is a view taken along the line 15-15 of FIG. 11; and

FIG. 16 is a view taken along the lines I6 16 of FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, andparticularly to FIGS. 1 and 2, there is designated generally byreference numeral an aquatic harvester in accordance with the presentinvention. The basic harvester component is the aquatic craft,designated generally by reference numeral 12, comprising a plurality ofpontoon members 14 secured beneath a flat deck member 16. The aquaticcraft is driven and steered by a completely above-the-water systemcomprising an air propulsion unit having an engine 22 and an aerodynamicpropeller 24, this unit being secured to a mounting means 26 which iscontrollably rotatable 360 about a vertical axis. At the forward end ofthe harvester there is mounted a pick-up assembly 30 which contains aconveyor 32 for picking up aquatic materials at and below the surface ofthe water and conveying the same onto the deck 16 of of aquatic craft12. As illustrated in FIG. I, the pick-up assembly may be rotated to anelevated position wherein it serves as an unloading means when conveyor32 is operated in the reverse or forward direction. In the preferredembodiment, the harvester ap paratus has a horizontal cutter barassembly 100 located adjacent the forward edge of the pick-up assembly.Most preferably. the cutter bar assembly is operated through directmechanical linkage with the pickup conveyor 32.

While the foregoing has briefly set forth and described the basiccomponents of the illustrated embodiment of the present aquaticharvester, each of the components will hereinafter be further describedin detail.

The aquatic craft comprises four pontoon member 14 secured beneath aflat deck 16 fabricated from wooden tongue and groove boards orconventional steel flooring strips which have been galvanized. Eachpontoon is constructed from a plurality of individual, interfittingsections 19 which are identical to one another save for the nosesections which are designed similar to the bow section of a boat inorder to facilitate movement of the craft through the water. The payloadcontaining section of the flat deck 16 is defined by the aforesaidportion constructed of flooring material, that portion being confined onthree sides by upstanding side rail member 17. The railing immediatelyforward of the air propulsion system is further provided with upwardlydirected louvers 18 which serve to deflect the air thrust away from thevehicle when the propulsion system is in the reverse position. Aft ofthe payload containing portion of the deck is located an auxiliary deckarea 11 fabricated from a light weight metallic mesh material as shownin FIG. 3. Forward of the payload deck area there is secured to theaquatic craft a support frame l3 for the pick-up assembly 30. Beneaththe deck 16 and between the pontoons is provided a suitable fuel tank61.

Overlying the deck member 16 is a bed conveyor comprising laterallyspaced endless conveyor chains 40 driven by common line shaft 42. Lineshaft 42 in turn is driven by a reversible motor 44, and thus, the bedconveyor is operable to convey in both the forward and aft directions.The endless bed conveyor chains also contain a series of upstandingteeth 46 spaced at intervals along the length of each chain to assist inthe movement of aquatic material contained on the deck of the craftduring harvesting operations. Also located near the forward end of thebed conveyor are a series of spaced deck risers 48 which aremechanically actuated into the rearwardly inclined position illustratedin FIGS. 1 and 7 to assist in transferring harvested aquatic materialfrom the bed conveyor to the pick-up conveyor when the machine isperforming its unloading function. Raising of the pick-up assembly toits unloading position mechanically positions the deck risers 48 intothe inclined position through a suitable linkage assembly.

The improved aspect of the present harvester consists in the design andstructure of the pontoon flotation system. Accordingly, it has beenfound in accordance with the present invention that certain pontoonmembers fabricated from molded thermoplastic or thermosetting syntheticresinous materials will provide a flotation system which is suitablyresistant to damage and at the same time provides suitable buoyantcapacity to achieve the desired payloads required for a successfulharvesting device. Each of the pontoon members comprises at least oneclosed, integrally formed buoyant capsule constructed of a syntheticresinous material. It is possible to achieve the additional advantagesindicated hereinabove by fabricating a single pontoon member so that itcontains a plurality of separate internal compartments, a feature whichis easily obtainable by employing known methods of construction forsynthetic resinous materials. However, the more preferred andillustrated embodiment of the present invention comprises forming eachof the four pontoon members 14 from a plurality of individual,interfitting capsules such as those designated by reference numberal 19in FIGS. 5 and 6. As is evident from these figures, each individualcapsule has a male portion 20 located at one end which is adapted tointerflt with a corresponding female portion contained in the oppositeend of an adjoining capsule. Each capsule is also provided with fourpairs of integrally molded flanges which are designed to facilitaterapid attachment to or removal from the aquatic harvester frame. Thismay be accomplished as illustrated in FIG. 9 by means of bolts 62 whichsimply pass through each pair of integrally molded flanges on thepontoon capsule and through each of four vertical truss members 112which extend the length of the aquatic craft and serve, together withtransversely extending truss members such as those designated byreference numeral 113 in FIGS. 1 and 9, to support the deck member 16.

Pontoon capsules of this type may be readily fabricated by means ofconventional molding techniques, and those constructed utilizingrotational casting techniques are especially suitable for the presentembodiment. In the presently preferred design for the pontoon capsulesillustrated in FIG. 6, each capsule consists of an integral moldedexterior shell 108 consisting of a solid, tough thermoplastic orthermosetting synthetic resinous material surrounding an internal cavity109. The internal cavity, whether within a single capsule or acompartmentalized pontoon, may optionally be partially or completelyfilled with a foamed material 107, preferably a closed-cell foamedsynthetic resinous material. Suitable synthetic resinous materials forforming the outer shell of the capsule include polyolefins such aspolyethylene, polypropylene, etc., styrene polymers includinghomopolystyrene, styrene copolymers and impact polystyrene, ABS typegraft copolymers, polyamides, polyesters, certain acrylic esterpolymers, polyurethanes and blends of the foregoing polymers. Fiberglass or other conventional reinforced plastic compositions may also beemployed. The optional foam filling in the interior of the capsule maybe formed from any of the foamed synthetic resinous materials, such asfoamed polystyrene, foamed polyurethane, foamed polyolefins, etc. In themost preferred embodiment of the invention, the pontoon sections areeach 36 inches long with a diameter of 26 inches, the outer shell beingformed of high impact resistant polyethylene and the interior beingapproximately one-half filled with a polyurethane foam. Each suchpontoon capsule is capable of providing over 700 pounds of totalflotation capacity. The resultant pontoons are extremely resistant toimpact damage and at the same time are non-rusting, completely inert andimpervious to gasoline, battery acid and similar volatile liquids.

The propulsion and steering system of the present invention isillustrated in FIGS. through 16. The basic propulsion unit consists ofan engine 22 preferably of the internal combustion type, but of anon-polluting nature, such as a 39l cubic inch V-8 Ford industrial typeengine adapted for a vapor fuel such as propane. The engine is operablyconnected through flexible belt 23 to the aerodynamic propeller 24.Contained internally of the engine 22 is a transmission which isoperable by means of lever 25 to engage and disengage the power supplyto belt 23 and hence to propeller 24. For safety reasons, there isprovided a cage type protector 27 around the propeller.

The propulsion system mounting assembly 26, illustrated in detail inFIGS. 12 through 16, also serves as the steering assembly for theaquatic craft. This assembly comprises a pair of superimposed annularmembers, consisting of a first annular member 50 and a second annularmember 52 each fabricated from angle iron in the illustrated embodiment.The first annular member 50 is rigidly secured adjacent the aft end ofthe aquatic craft by suitable support members, whereas the secondannular member 52 is of slightly smaller diameter than the firstannulus, and hence, when concentrically superimposed thereon restsinside the first annular member and is confined thereby so as to beradially immovable with respect thereto. See FIGS. and 16. However,because annulus 52 is freely resting upon annulus 50, the former isfreely rotatable through an angle of 360 about the common vertical axisof the annuli. The two annular members are of sufficient diameter tounderlie a substantial portion of the propulsion unit in order toprovide adequate support and stability therefor. Typically, there isprovided bearing members between the two annular members to facilitaterotational movement therebetween. Identified by reference numeral 54 inFIG. 15, such bearing members are preferably fabricated of fiberglass orother synthetic resin laminated or bonded material to serve additionallyas vibrating and shock absorbing members. These bearing members may alsobe channeled and provided with grease fittings to further enhance theirutility as bearings. To the upper surface of the second annular member52 there is secured mounting means in the form of framework 58 for theengine and air propulsion unit.

There is also provided novel rotational means for the steering assemblycomprising annular sprocket 70 secured to the second annular member 52through the engine mounting structure 58. Sprockets 78, and hence thesteering assembly, are driven selectively in either the clockwise orcounter clockwise direction by reversible electric motor 72 actingthrough a suitable gear reducer 74 and roller chain 76. Reversibleelectric motor 72 is a 12 volt DC motor supplied with electrical energyfrom the ignition system of engine 22. This rotational means provides asteering system which is simple, dependable and practically fail safe,and one which can easily and inexpensively operate from a remoteposition through simple electrical control circuitry. Thus, at all timeswhen the engine is running, and even when the ignition is merely in theon position, complete control is achieved over rotation of the airpropulsion unit. The aforementioned remote control system is preferablyone wherein rotation is initiated by simple selection and depression ofeither a clockwise or a counter clockwise rotation button or switch.Rotation proceeds only when the switch or button is held in the "onposition by the operator. However, to further assist the operator, therotation system may additionally be provided with cut-of switches at the90 positions about the annular members 50 and 52, whereby rotation willautomatically stop as the propulsion unit is rotated past any one of thefour points regardless of whether the operator continues to hold thecontrol switch in the on" position.

In FIG. 14 there is illustrated a typical chain tightener assemblyadapted to take up the slack when sprocket and roller chain 76 arerotated in either the clockwise or counter clockwise direction. Thechain tightener system comprises two stationary bars 80 and 82 securedto stationary annular member 50 through structural support member 81,said bar members 80 and 82 being biased towards one another by spring85. This biasing action forces cam rollers 86 and 87 mounted at the endof the two bar members, 80 and 82 respectively, against roller chain 76.Hence, as illustrated in FIG. 14, when sprocket 70 is rotated in theclockwise direction chain slack is taken up by roller 87.

In FIG. 16 there is illustrated a feature which can be optionallyincorporated into the steering assembly. This feature consists of anangular bracket 91 secured to the second annular member 52, said bracketdepending outwardly and downwardly therefrom to a point below thehorizontal flange of first annular member 50. A bearing roller is thendisposed inwardly from the downwardly depending section of bracket 91passing beneath the horizontal flange of annulus 50 to provide a safetyfeature preventing accidental disengagement of annular members 50 and52.

Referring now to FIGS. 1, 4, 7 and 8 wherein there is illustrated thepick-up assembly designated generally by reference numeral 30, it isseen that this assembly comprises a pair of laterally spaced trussmembers 33 and 34 rotatably mounted near the upper or aft ends thereofto support frame 13 secured to the aquatic craft l2. Overlying the twotruss members 33 and 34 and extending the full width of the aquaticcraft I2 is a continuous mesh surface 35 supported by suitablereinforcing means. Previously mentioned pick-up conveyor 32 in turnoverlies the mesh surface of the pick-up assembly. This conveyorconsists of a series of pairs of endless conveyor chains 36, the chainsof each pair being interconnected by lateral members 37 at spacedintervals along their lengths. It is preferred that at least a portionof each lateral connector 37 extend upwardly from the plane defined bythe conveyor chains 36. Like the bed conveyor means on the deck member16, the pick-up conveyor is selectively operable to convey in both thefore and aft directions, and like the bed conveyor, it is driven by areversible motor 39 located adjacent the aft portion of the pick-upassembly.

As illustrated in FIGS. 1 and 7, the pick-up assembly 30 may be rotatedabout the horizontal axis defined by its mounting points on supportmember 13. Thus, the forward end of the pick-up assembly may bepositioned at elevations below the surface of the water or above thedeck of the aquatic vehicle, or held at any elevation therebetween. Theuppermost position of the pick-up assembly defines the unloadingposition wherein the aft end of the pick-up conveyor is rotated to aposition contiguous with the bed conveyor. [n this position, both thepick-up and bed conveyors may be operated to convey in the forwarddirection whereupon the payload of harvested aquatic material will beautomatically unloaded from the deck of the aquatic craft.

The assembly employed to rotate the pick-up assembly about theaforementioned horizontal axis is illustrated in detail in FIGS. 7 and8. Referred to herein as the actuator assembly, it comprises a basicpower source consisting of a motor 95 which in turn operates a lineshaft 96 through a suitable chain and sprocket assembly. The line shaftcarries a sprocket 97 beneath truss members 33 and 34 underlying eachside of the pick-up assembly. A finite length of roller chain is securedto truss member 33 adjacent the aft end thereof, said roller chain thenextending downwardly and around idler sprocket 94 mounted on the aquaticcraft, and thence back up and around idler sprocket 93 secured on thepick-up assembly truss member After passing over idler sprocket 93,roller chain 99 again passes down and around drive sprocket 97 securedon the line shaft 96. Roller chain 99 is caused to pass around the majorportion of the circumference of sprocket 97 by passing the same aroundanother idler sprocket 98 mounted adjacent and immediately above thedrive sprocket 97, whereupon there is provided absolute engagement ofthe roller chain 99 about the drive sprocket to accurately control thedegree of rotation of the pick-up assembly. The foregoing roller chainassembly is duplicated identically beneath the second pick-up assemblytruss member 34 and thus the delineated structure serves the importantpurpose of assuring uniform rotational adjustment across the entirelength of the pick-up assembly. Such uniform adjustment is difficultlyattained with similar winch assemblies. The free end of roller chain 99,as it drops off idler sprocket 98, is collected into a suitablereceptacle 90 positioned between the pontoon members 14. Likewisepositioned therebetween, is a spring assist member 89 to counterbalancethe weight of the pick-up assembly and aid in the rotation thereof.Again, identical spring assist members are provided beneath each of thetruss members 33 and 34.

The control system employed to operate the various subassemblies in thepresent harvesting device may consist either of a conventional hydraulicsystem of the type utilized in many prior art harvester apparatus or thethree-phase 230 volt electrical system described in my prior US. Pat.'No. 3,698,163.

It will be appreciated that the aquatic harvester of the presentinvention, like that of my original invention, finds many applicationsnot requiring the presence of a cutting means, e.g., picking up floatingaquatic weed growth both at and below the surface of the water,

picking up floating debris from the water, picking up objects off thebottom of a body of water, etc. Likewise, when it is desired to includea cutting means adjacent the forward edge of the pick-up assembly, itwill be appreciated that any of the conventional type of cutter bardesigns may be employed for this purpose. FIGS. 1 and 7 generallyillustrate a cutter bar mechanism located adjacent the forward edge ofthe pick-up assembly 30. As illustrated in FIG. 4, the second or lowercutter bar 111 is mounted stationary upon the pick-up assembly 30 of theaquatic harvester. The first or upper cutter bar severed served at itsmid-point into two sections of equal length and each section ispositioned in lateral sliding relationship with stationary cutter bar111. The two sections of upper cutter bar 110 are then provided withmechanical driving means in the form of cam disks 115 connected tocommon line shaft 116 carrying the pick-up apparatus conveyor chains.Rotation of shaft 116 and concomitant rotation of cammed disks 115results in reciprocation of the two sections of top cutter bar 110. Itis observed that the two cutter bar sections are timed to reciprocateout of phase with one another, whereupon there is provided a highlyeffective means of cancelling substantially all vibration resulting fromreciprocation of the cutter bar mechanism.

Preferably, mechanical linkage or other means are provided to maintainthe cutter bar assembly in the position coplanar with the surface of thewater, i.e., horizontal, as the pick-up assembly is raised and loweredto vary the cutting depth of the apparatus. Advantageously, the samelinkage serves to rotate the cutter bar into a non-interferring positionwhen the pick-up assembly is positioned to unload harvested payload. Thesimplest mechanical linkage consisting of one or more elongated members118 (FIGS. 1 and 7) extending from the cutter bar assembly to supportframe 13, and hingedly connected to each, will readily suffice.

A representative aquatic harvester designed in accordance with theforegoing principles and embodying the various hereinabove delineatedcomponent systems is constructed utilizing four pontoon members, eachconsisting of 17 separate 36-inch pontoon capsules of 26- inch diameter,thus giving a total pontoon length of SI feet. The total length of theharvester is approximately 70 feet and the overall width is 18 feetallowing a cutting swath of approximately 16 feet. This harvester iscapable of carrying a payload of 21,000 pounds or a volume of 2,l00cubic feet, while at the same time having a water draft of l2 inches inthe unloaded condition and only 20 inches in the fully loaded condition.

Operation of the present harvesting apparatus is essentially identicalto that described in my earlier patent for the basic harvester.

While the present invention has been described with reference to asingle illustrated embodiment, it is to be understood that many obviousmodifications, which will be readily apparent to a person of ordinaryskill in the art, may be made to the subject aquatic harvester withoutdeparting from the spirit of the present invention. Accordingly, thescope of protection is to be limited only by the claims which follow.

What is claimed is:

1. An aquatic harvester comprising an aquatic craft having a pluralityof pontoon members secured longitudinally beneath a deck member saiddeck member being adapted to receive a payload of harvested aquaticmaterial,

a pick-up assembly mounted on said craft for aquatic material both atand below the surface of the water and as the sole means of propulsionan steering, a single above-the-water propulsion and steering systemhaving an air propulsion unit, mounting means for said air propulsionunit capable of rotating 360 about a vertical axis, wherein said unitcomprises an engine, an aerodynamic propeller and means connecting thecrankshaft of said engine to the propeller,

each of said pontoon members comprising at least one closed, integrallyformed buoyant capsule con structed of a synthetic resinous material.

2. The aquatic harvester according and claim I, wherein each of saidpontoon members comprises a plurality of said thermoplastic syntheticresinous capsules.

3. The aquatic harvester according to claim 2, wherein saidthermoplastic synthetic resinous capsules comprise an integral moldedexterior shell surrounding an internal cavity.

4. The aquatic harvester according to claim 3, wherein said internalcavity is at least partially filled with a foamed material.

5. The aquatic harvester according to claim 4, wherein said exteriorshell is constructed of polyethyl ene and said foamed material is asynthetic resinous material selected from the group consisting ofpolystyrene and polyurethane.

6. The aquatic harvester according to claim 1, wherein each of saidpontoon members comprises a single capsule having a plurality ofindividually sealed internal compartments.

7. The aquatic harvester according to claim 6, wherein each of saidinternal compartments is at least partially filled with a foamedmaterial.

8. An aquatic harvester according to claim I, further comprising a bedconveyor means overlying the deck member, said conveyor means beingselectively operable to convey in fore and aft directions.

9. An aquatic harvester according to claim 1, further comprisingmounting means pivotally connecting the pick-up assembly to the aquaticcraft so that said assembly projects forward of said craft and isrotatable about a horizontal axis, and actuating means for rotating saidassembly to vary the elevation of the forward end of said assembly andto hold the assembly at selected elevations.

10. An aquatic harvester according to claim 1, further comprising apick-up assembly conveyor means which is operable to convey in both thefore and aft directions, whereby said pick-up assembly serves as anunloading means when the aft end of said pick-up assembly conveyor isrotated to a position contiguous with the bed conveyor means.

I]. An aquatic harvester according to claim 8, further comprising ahorizontal cutter means located adjacent the forward edge of the pick-upassembly and mechanical operating means for said cutter means, saidoperating means being driven by the pick-up conveyor means.

1. An aquatic harvester comprising an aquatic craft having a pluralityof pontoon members secured longitudinally beneath a deck member saiddeck member being adapted to receive a payload of harvested aquaticmaterial, a pick-up assembly mounted on said craft for aquatic materialboth at and below the surface of the water and as the sole means ofpropulsion an steering, a single above-thewater propulsion and steeringsystem having an air propulsion unit, mounting means for said airpropulsion unit capable of rotating 360* about a vertical axis, whereinsaid unit comprises an engine, an aerodynamic propeller and meansconnecting the crankshaft of said engine to the propeller, each of saidpontoon members comprising at least one closed, integrally formedbuoyant capsule constructed of a synthetic resinous material.
 2. Theaquatic harvester according and claim 1, wherein each of said pontoonmembers comprises a plurality of said thermoplastic synthetic resinouscapsules.
 3. The aquatic harvester according to claim 2, wherein saidthermoplastic synthetic resinous capsules comprise an integral moldedexterior shell surrounding an internal cavity.
 4. The aquatic harvesteraccording to claim 3, wherein said internal cavity is at least partiallyfilled with a foamed material.
 5. The aquatic harvester according toclaim 4, wherein said exterior shell is constructed of polyethylene andsaid foamed material is a synthetic resinous material selected from thegroup consisting of polystyrene and polyurethane.
 6. The aquaticharvester according to claim 1, wherein each of said pontoon memberscomprises a single capsule having a plurality of individually sealedinternal compartments.
 7. The aquatic harvester according to claim 6,wherein each of said internal compartments is at least partially filledwith a foamed material.
 8. An aquatic harvester according to claim 1,further comprising a bed conveyor means overlying the deck member, saidconveyor means being selectively operable to convey in fore and aftdirections.
 9. An aquatic harvester according to claim 1, furthercomprising mounting means pivotally connecting the pick-up assembly tothe aquatic craft so that said assembly projects forward of said craftand is rotatable about a horizontal axis, and actuating means forrotating said assembly to vary the elevation of the forward end of saidassembly and to hold the assembly at selected elevations.
 10. An aquaticharvester according to claim 1, further comprising a pick-up assemblyconveyor means which is operable to convey in both the fore and aftdirections, whereby said pick-up assembly serves as an unloading meanswhen the aft end of said pick-up assembly conveyor is rotated to aposition contiguous with the bed conveyor means.
 11. An aquaticharvester according to claim 8, further comprising a horizontal cuttermeans located adjacent the forward edge of the pick-up assembly andmechanical operating means for said cutter means, said operating meansbeing driven by the pick-up conveyor means.